Melatonin for jet lag

Melatonin is effective in reducing jet lag, but you must use the right type and dose at the right time, and also time your light exposure correctly.

Reviewed by:
Steven W. Lockley, Ph.D.
Chief Scientist, Timeshifter

What is melatonin?

Melatonin is a natural hormone, produced by the pineal gland in the brain and is only released at night. It is sometimes called the ‘hormone of darkness’. The release of melatonin is controlled by the 24-hour circadian clock, and tells the brain it’s nighttime. While melatonin is not a sleep hormone, in day-active animals like humans, melatonin ‘opens the sleep gate’ and tells the brain it’s time to sleep. We usually start to release melatonin about 2-3 hours before we go to sleep. Melatonin can also be purchased in a pill form, which contain a synthetic version of the hormone but in a much higher dose than we naturally produce. Melatonin is the only time cue other than light that can shift the circadian clock and help you shift to new time zones even faster, although its effects are generally weaker than light.

How can melatonin help me reduce jet lag when I travel?

Light is the most important time cue for resetting your circadian clock. Managing when you see and avoid light is critical to adapting to new time zones quickly. However, the right type and dose of melatonin, at the right time, can help you shift even faster and sleep better as you are transitioning between time zones. If you take melatonin, but your light exposure isn’t timed correctly, melatonin may not help you adapt to your new time zone any faster.

Taking melatonin will do two things: First, it will help shift the timing of the circadian clock to help you overcome jet lag more quickly. Second, it will help you sleep when you are transitioning between time zones by telling the brain to sleep at a different time than normal. Melatonin is not a sleeping pill, however, and will not help sleep once your jet lag is gone.

How does melatonin help adjust circadian rhythms?

Melatonin pills can help regulate the circadian clock by shifting the timing of internal rhythms. Receptors for melatonin are located in the suprachiasmatic nuclei, the location of the circadian pacemaker, and can reset the rhythms generated by the pacemaker. Melatonin taken in the evening will shift the clock earlier (a phase advance) whereas melatonin taken in the morning will shift the clock later (a phase delay). Taking melatonin at the right time for the required shift will help reset the clock more quickly when traveling across time zones.

Melatonin can also help reset the clock indirectly through its influence on sleep, and therefore light-dark exposure. Melatonin pills can promote sleep when you are not releasing your own melatonin and this will in turn affect your light-dark exposure (as closing your eyes to sleep will reduce the amount of light reaching the retinae and therefore the circadian clock).

These combined effects of melatonin, when timed properly, will help reset the clock and overcome your jet lag quicker.

What type and dosage of melatonin should I use for jet lag?

Use a low-dose (1-3mg) fast release preparation when indicated to help reset the clock (slow release formulations and higher doses are available but they may stay in the system too long and confuse the circadian clock). 

As melatonin is considered a food supplement in the USA, the manufacture and sale of melatonin are less controlled than prescription drugs, so there may be considerable variation in the quality and melatonin dose across products. It's also often sold combined with other substances, such as Valerian or St John's Wort. If you choose to buy a food supplement version of melatonin, use a ‘melatonin-only' product, without additional substances, and buy it from a reputable pharmacy (they often have own label preparations).

A fast-release pill form is likely to provide a more reliable dose than melatonin-containing drinks or sprays. There's no evidence that products high in tryptophan, from which melatonin is synthesized, or melatonin such as cherry juice, can help shift the circadian clock.

Should melatonin for jet lag be taken in the morning or evening?

The timing of melatonin administration is dependent on many factors, including the resetting effects required, the time of the flight, and your chronotype and desired sleep time. There are also times when melatonin should not be taken if it could increase the risk of undesired drowsiness (i.e. while driving).

There is no simple rule of thumb for when to take melatonin when traveling, and two people might need different times even for the same flight based on their personal preferences.

Timeshifter’s jet lag app provides highly personalized information based on user preferences and flight information about when to take melatonin, if the user chooses to. The advice will start several days before the trip to help adapt as quickly as possible once you arrive at your destination. Taking melatonin as suggested by the App will be helpful but is not required to overcome jet lag - most of the resetting effects are realized through the light-dark advice.

Other things you can do to complement melatonin for jet lag

The most important factors for overcoming jet lag are when to see light and when to avoid light – the light-dark cycle. Timeshifter’s jet lag app provides practical information on when to see or avoid light, which can be as simple as getting outside or turning on the light indoors when you need to see light, or putting on sunglasses and making lights as dim as possible when you need to avoid light. For melatonin, the timing of light and dark exposure is key and therefore Timeshifter provides personalized advice based on user preferences and flight details.

Other factors that can help include caffeine and napping. As always, the correct timing is important and Timeshifter provides plans on how and when to use caffeine, and when to nap. This advice not only helps your alertness directly but will also help you follow the light advice by staying awake or sleeping at the right times.

While many claims are made for jet lag solutions, such as acupuncture, fasting and hydration, none of these reset the circadian pacemaker. While they may help you feel better, they cannot address the underlying cause of jet lag.

Is melatonin safe to use for jet lag?

Warnings:

  1. Melatonin is a relatively safe supplement when used in the short-term, and melatonin side effects are uncommon. Headache, sleepiness, vivid dreams, and nausea have been reported.

  2. Melatonin safety in the long-term has NOT been determined in randomized, controlled studies.

  3. You may NOT be able to use melatonin if you have certain medical conditions. Do NOT use melatonin without medical advice.

  4. There is NO data on how melatonin interacts with other drugs. Do NOT use melatonin with antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), or with sleeping pills.

  5. Do NOT use melatonin if you are pregnant, lactating, have epilepsy or migraines, taking warfarin, or if you have a personal or family history of psychiatric disorders.

  6. AVOID alcohol and tasks requiring a high level of alertness, such as driving or operating machinery, within 8 hours after taking melatonin.

  7. Try melatonin at home or in a safe environment BEFORE using it on your first trip. NEVER take melatonin for the first time on the plane.

  8. Do NOT give melatonin to children.

Before using a specific melatonin product, make sure to ask your doctor about its safety, side effects, interactions, and warnings. If you experience side effects after taking melatonin, you must consult your doctor.

App with melatonin advice for jet lag

Taking melatonin at the right time can help you shift more quickly to a new time zone, but the right light exposure at the right time is even more effective if you are trying to eliminate jet lag. The Timeshifter jet lag app will give you all the advice you need when crossing time zones, including when to use melatonin during your trips to get the maximum benefits. Try it free on your next trip.

Jet lag is history.

Timeshifter's jet lag app is the most-downloaded and highest-rated jet lag app in the world. Get personalized jet lag plans based on your sleep pattern, chronotype, itinerary, and personal preferences.

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